The Hero is a Girl?!

I had a crush on my campus idol Luna. And one day the girl belonged to me flesh and soul, but not in my way, we exchanged our bodies. I became her! And her fragile body and D cup were all mine! All this is to blame a weird guy claimed to be a magician from another world. And he called me Hero who was to save the world which was in danger. So the Hero has to save the world meanwhile protecting his/ her body from bad guys and lesbian girls.